Add TransmogrificationConfig for Google importers

[incjo]

Currently, transmogrification logic is being duplicated in the Google adapter code. Add a TransmogrificationConfig to fix this.

[sreenath-tm]

I'm interested in contributing to this issue, so before I start working it, would anyone mind sparing a little time explaining what the issue is about and pointing me to some resources to get started.

[incjo]

When dealing with the album, photo and video names and descriptions, Google adapters manually sanitise the strings. Instead, it's meant to be dealt by implementing a Google specific TransmogrificationConfig. It should be fairly straightforward. Look at how other such configs are used, do something similar and remove explicit name truncation from the adapter code.